Light-emitting device and apparatus including same

ABSTRACT

A light-emitting device and an apparatus including the same include a first electrode, a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, wherein the organic layer includes m emission units and (m−1) charge generating units, each of the charge generating units being between the emission units that are adjacent to each other, m is a natural number of 2 or greater, at least one of the (m−1) charge generating units includes an n-type charge generating layer, a p-type charge generating layer, and a p-type hole injection layer, wherein the n-type charge generating layer includes an n-type organic compound and a metal material, and wherein the p-type charge generating layer and the p-type hole injection layer each independently include an inorganic semiconductor material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of Korean PatentApplication No. 10-2020-0043603, filed on Apr. 9, 2020 and Korean PatentApplication No. 10-2021-0012657, filed on Jan. 28, 2021, which arehereby incorporated by reference for all purposes as if fully set forthherein.

BACKGROUND Field

One or more embodiments relate to a light-emitting device and a deviceincluding the light-emitting device.

Discussion of the Background

Light-emitting devices are devices that convert electrical energy intolight energy. Examples of such light-emitting devices include organiclight-emitting devices using organic materials for an emission layer,quantum dot light-emitting devices using quantum dots for an emissionlayer, and the like.

Light-emitting devices may include a first electrode on a substrate, anda hole transport region, an emission layer, an electron transportregion, and a second electrode sequentially stacked on the firstelectrode. Holes provided from the first electrode may move toward theemission layer through the hole transport region, and electrons providedfrom the second electrode may move toward the emission layer through theelectron transport region. Carriers, such as holes and electrons,recombine in the emission layer to produce excitons. These excitonstransit from an excited state to a ground state to thereby generatelight.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

One or more embodiments relate to a tandem light-emitting device havinga low driving voltage and excellent efficiency and lifespancharacteristics by balance optimization of holes and electrons and anapparatus including the tandem light-emitting device.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments of the disclosure.

According to one or more embodiments, a light-emitting device mayinclude a first electrode, a second electrode facing the firstelectrode, and an organic layer between the first electrode and thesecond electrode, wherein the organic layer may include m emission unitsand (m−1) charge generating units, each of the charge generating unitsbeing between the emission units that are adjacent to each other,

m may be a natural number of 2 or greater,

at least one of the (m−1) charge generating units may include an n-typecharge generating layer, a p-type charge generating layer, and a p-typehole injection layer,

the n-type charge generating layer may include an n-type organiccompound and a metal material, and

the p-type charge generating layer and the p-type hole injection layermay each independently include an inorganic semiconductor material.

According to one or more embodiments, an apparatus may include athin-film transistor including a source electrode, a drain electrode,and an active layer, and the light-emitting device, wherein a firstelectrode of the light-emitting device may be electrically connected toany one of the source electrode and the drain electrode of the thin-filmtransistor.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary illustrative andexplanatory and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary illustrativeembodiments of the invention, and together with the description serve toexplain the inventive concepts.

FIG. 1 is a schematic cross-sectional view illustrating a light-emittingdevice according to an embodiment;

FIG. 2 is an enlarged cross-sectional view illustrating a chargegenerating unit shown in FIG. 1 ;

FIG. 3 and FIG. 4 are each a schematic cross-sectional view illustratinga light-emitting device according to an embodiment; and

FIG. 5 is a schematic cross-sectional view illustrating an emissionapparatus according to an embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various embodiments may bepracticed without these specific details or with one or more equivalentarrangements. In other instances, well-known structures and devices areillustrated in block diagram form in order to avoid unnecessarilyobscuring various embodiments. Further, various embodiments may bedifferent, but do not have to be exclusive. For example, specificshapes, configurations, and characteristics of an embodiment may be usedor implemented in another embodiment without departing from theinventive concepts.

Unless otherwise specified, the illustrated embodiments are to beunderstood as providing illustrative features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anembodiment may be implemented differently, a specific process order maybe performed differently from the described order. For example, twoconsecutively described processes may be performed substantially at thesame time or performed in an order opposite to the described order.Also, like reference numerals denote like elements.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the term“below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Reference will be made in detail to embodiments, examples of which areillustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Throughout the disclosure, the expression “atleast one of a, b or c” indicates only a, only b, only c, both a and b,both a and c, both b and c, all of a, b, and c, or variations thereof.

As the inventive concept allows for various changes and numerousembodiments, particular embodiments will be illustrated in the drawingsand described in detail in the written description. Effects, features,and a method of achieving the inventive concept will be obvious byreferring to example embodiments of the inventive concept with referenceto the attached drawings. The inventive concept may, however, beembodied in many different forms and should not be construed as beinglimited to the embodiments set forth herein.

Hereinafter, the inventive concept will be described in detail byexplaining example embodiments of the inventive concept with referenceto the attached drawings. Like reference numerals in the drawings denotelike elements, and thus their description will be omitted.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another.

In the embodiments described in the present specification, an expressionused in the singular encompasses the expression of the plural, unless ithas a different meaning in the context.

In the present specification, it is to be understood that the terms suchas “including,” “having,” and “comprising” are intended to indicate theexistence of the features or components disclosed in the specification,and are not intended to preclude the possibility that one or more otherfeatures or components may exist or may be added.

It will be understood that when a layer, region, or component isreferred to as being “on” or “onto” another layer, region, or component,it may be directly or indirectly formed over the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

Sizes of components in the drawings may be exaggerated for convenienceof explanation. In other words, because sizes and thicknesses ofcomponents in the drawings are arbitrarily illustrated for convenienceof explanation, the following embodiments are not limited thereto.

It will be understood that when a layer, region, or component isreferred to as being “connected to” another layer, region, or component,the layer, region, or component may be directly connected to the anotherlayer, region, or component, or indirectly connected to the anotherlayer, region, or component as intervening layer, region, or componentis present. For example, it will be understood that when a layer,region, or component is referred to as being “electrically connected to”another layer, region, or component, the layer, region, or component maybe directly electrically connected to the another layer, region, orcomponent, or indirectly electrically connected to the another layer,region, or component as interventing layer, region, or component ispresent.

As used herein, the expression the “(organic layer) includes a compoundrepresented by Formula 1” may be construed as meaning the “(organiclayer) may include one compound that is represented by Formula 1 or twodifferent compounds that are represented by Formula 1”.

In the present specification, the term “Group” refers to a group on theIUPAC Periodic Table of Elements.

In the present specification, the term “alkali metal” refers to a Group1 element. In detail, an alkali metal may be lithium (Li), sodium (Na),potassium (K), rubidium (Rb), or cesium (Cs).

In the present specification, the term “alkali earth metal” refers to aGroup 2 element. In detail, an alkaline earth metal may be magnesium(Mg), calcium (Ca), strontium (Sr), or barium (Ba).

In the present specification, the term “lanthanide metal” refers to thelanthanide or a lanthanoid series of elements. In detail, a lanthanidemetal may be lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium(Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd),terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm),ytterbium (Yb), or lutetium (Lu).

In the present specification, the term “transition metal” refers to anelement belonging to Periods 4 to 7 and Groups 3 to 12. In detail, atransition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf),vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum(Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron(Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium(Ir), nickel(Ni), palladium (Pd), platinum (Pt), copper(Cu), silver(Ag), gold (Au), zinc(Zn), or cadmium (Cd).

In the present specification, the term “post-transition metal” refers toan element belonging to Periods 3 to 7 and Groups 13 to 17. In detail, apost-transition metal may be aluminum (Al), gallium (Ga), indium (In),thallium (Tl), tin (Sn), lead (Pb), bismuth (Bi), or polonium (Po).

In the present specification, the term “halogen” refers to a Group 17element. In detail, halogen may be fluorine (F), chlorine (Cl), bromine(Br), or iodine (I).

In the present specification, the term “inorganic semiconductormaterial” refers to a material that is an inorganic material and has aband gap less than 4 electron volts (eV). In detail, the inorganicsemiconductor material may include a post-transition metal, a halide ofa lanthanide metal, a halide of a transition metal, a halide of apost-transition metal, bismuth, tellurium, a telluride of a lanthanidemetal, a telluride of a transition metal, a telluride of apost-transition metal, a sulfide of a lanthanide metal, a sulfide of atransition metal, a sulfide of a post-transition metal, a selenide of alanthanide metal, a selenide of a transition metal, a selenide of apost-transition metal, or any combination thereof. In detail, theinorganic semiconductor material may be EuI₂, YbI₂, SmI₂, TmI₂, AgI,CuI, NiI₂, CoI₂, BiF₃, BiCl₃, BiBr₃, BiI₃, PbI₂, SnI₂, Bi, Te, EuTe,YbTe, SmTe, TmTe, EuSe, YbSe, SmSe, TmSe, ZnTe, CoTe, Bi₂S₃, Bi₂Se₃,ZnSe, CoSe, Bi₂Te₃, Bi₂Se₃, or any combination thereof.

In the present specification, the term “inorganic insulating material”refers to a compound that is an inorganic material and has a band gap of4 eV or higher. In detail, the inorganic insulating material may includea halide of an alkali metal, a halide of an alkaline earth metal, ahalide of a lanthanide metal, or any combination thereof. In detail, theinorganic insulating material may include NaI, KI, RbI, CsI, NaCl, KCl,RbCl, CsCl, NaF, KF, RbF, CsF, MgI₂, CaI₂, SrI₂, BaI₂, MgCl₂, CaCl₂,SrCl₂, BaCl₂, MgF₂, CaF₂, SrF₂, BaF₂, EuI₃, YbI₃, SmI₃, TmI₃, EuCl₃,YbCl₃, SmCl₃, TmCl₃, EuF₃, YbF₃, SmF₃, TmF₃, or any combination thereof.

In the present specification, the term “halide of an alkali metal”refers to a compound in which an alkali metal is ion-bonded to halogen.In detail, a halide of an alkali metal may include NaI, KI, RbI, CsI,NaCl, KCl, RbCl, CsCl, NaF, KF, RbF, CsF, or any combination thereof.

In the present specification, the term “halide of an alkaline earthmetal” refers to a compound in which an alkaline earth metal ision-bonded to halogen. In detail, a halide of an alkaline earth metalmay include MgI₂, CaI₂, SrI₂, BaI₂, MgCl₂, CaCl₂), SrCl₂, BaCl₂, MgF₂,CaF₂, SrF₂, BaF₂, or any combination thereof.

In the present specification, the term “halide of a lanthanide metal”refers to a compound in which a lanthanide metal is ion-bonded and/orcovalent-bonded to halogen. In detail, a halide of a lanthanide metalmay include EuI₂, YbI₂, SmI₂, TmI₂, EuI₃, YbI₃, SmI₃, TmI₃, EuCl₃,YbCl₃, SmCl₃, TmCl₃, EuF₃, YbF₃, SmF₃, TmF₃, or any combination thereof.

In the present specification, the term “halide of a transition metal”refers to a compound in which a transition metal is ion-bonded and/orcovalent-bonded to halogen. In detail, a halide of a transition metalmay include AgI, CuI, NiI₂, CoI₂, or any combination thereof.

In the present specification, the term “halide of a post-transitionmetal” refers to a compound in which a post-transition metal ision-bonded and/or covalent-bonded to halogen. In detail, a halide of apost-transition metal may include BiI₃, PbI₂, SnI₂, or any combinationthereof.

In the present specification, the term “telluride of a lanthanide metal”refers to a compound in which a lanthanide metal is ion-bonded,covalent-bonded, and/or metal-bonded to tellurium (Te). In detail, atelluride of a lanthanide metal may include EuTe, YbTe, SmTe, TmTe, orany combination thereof.

In the present specification, the term “telluride of a transition metal”refers to a compound in which a transition metal is ion-bonded,covalent-bonded, and/or metal-bonded to tellurium (Te). In detail, atelluride of a transition metal may include ZnTe, CoTe, or anycombination thereof.

In the present specification, the term “telluride of a post-transitionmetal” refers to a compound in which a post-transition metal ision-bonded, covalent-bonded, and/or metal-bonded to tellurium (Te). Indetail, a telluride of a post-transition metal may include Bi₂Te₃.

In the present specification, the term “sulfide of a lanthanide metal”refers to a compound in which a lanthanide metal is ion-bonded,covalent-bonded, and/or metal-bonded to sulfur (S). In detail, a sulfideof a lanthanide metal may include EuS, YbS, SmS, TmS, or any combinationthereof.

In the present specification, the term “sulfide of a transition metal”refers to a compound in which a transition metal is ion-bonded,covalent-bonded, and/or metal-bonded to sulfur (S). In detail, a sulfideof a transition metal may include ZnS, CoS, or any combination thereof.

In the present specification, the term “sulfide of a post-transitionmetal” refers to a compound in which a post-transition metal ision-bonded, covalent-bonded, and/or metal-bonded to sulfur (S). Indetail, a sulfide of a post-transition metal may include Bi₂S₃.

In the present specification, the term “selenide of a lanthanide metal”refers to a compound in which a lanthanide metal is ion-bonded,covalent-bonded, and/or metal-bonded to selenium (Se). In detail, aselenide of a lanthanide metal may include EuSe, YbSe, SmSe, TmSe, orany combination thereof.

In the present specification, the term “selenide of a transition metal”refers to a compound in which a transition metal is ion-bonded,covalent-bonded, and/or metal-bonded to selenium (Se). In detail, aselenide of a transition metal may include ZnSe, CoSe, or anycombination thereof.

In the present specification, the term “selenide of a post-transitionmetal” refers to a compound in which a post-transition metal ision-bonded, covalent-bonded, and/or metal-bonded to selenium (Se). Indetail, a selenide of a post-transition metal may include Bi₂Se₃.

According to an embodiment, a light-emitting device may include a firstelectrode; a second electrode facing the first electrode; and an organiclayer between the first electrode and the second electrode,

wherein the organic layer may include m emission units and (m−1) chargegenerating units, each of the charge generating units being between theemission units that are adjacent to each other, m may be a naturalnumber of 2 or greater,

At least one of the (m−1) charge generating units may include an n-typecharge generating layer, a p-type charge generating layer, and a p-typehole injection layer,

The n-type charge generating layer may include an n-type organiccompound and a metal material, and

The p-type charge generating layer and the p-type hole injection layermay each independently include an inorganic semiconductor material.

In the light-emitting device, the p-type charge generating layer and thep-type hole injection layer included in the hole transporting unit mayeach independently include an inorganic semiconductor material.Accordingly, in the light-emitting device, charge generation andmigration may be facilitated at an interface between the chargegenerating units, and deterioration of materials at an interface betweenlayers may be prevented to thereby suppress an increase in drivingvoltage and provide improved lifespan and/or luminance.

Description of FIG. 1

FIG. 1 is a schematic cross-sectional view illustrating a light-emittingdevice according to an embodiment.

As illustrated in FIG. 1 , a light-emitting device 1 according to anembodiment may include a first electrode 110; a second electrode 190facing the first electrode 110; m emission units ELU(1) to ELU(m)between the first electrode 110 and the second electrode 190; and (m−1)charge generating units CGU(1) (not shown) to CGU(m−1), each of thecharge generating units being between the emission units that areadjacent to each other, wherein m may be a natural number of 2 orgreater, each of the emission units may include an emission layer, andat least one of the (m−1) charge generating units may include an n-typecharge generating layer and a p-type charge generating layer.

Hereinafter, the light-emitting device 1 according to an embodiment willbe described in connection with FIG. 1 .

Features related to the first electrode are described herein.

In FIG. 1 , a substrate may be additionally disposed under the firstelectrode 110 or above the second electrode 190. The substrate may be aglass substrate or a plastic substrate, each having excellent mechanicalstrength, thermal stability, transparency, surface smoothness, ease ofhandling, and water resistance.

The first electrode 110 may be formed by depositing or sputtering, ontothe substrate, a material to form the first electrode 110. When thefirst electrode 110 is an anode, the material to form the firstelectrode 110 may be selected from materials with a high work functionthat facilitate hole injection.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material to form the firstelectrode 110 may be selected from indium tin oxide (ITO), indium zincoxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinationsthereof, but embodiments are not limited thereto. In some embodiments,when the first electrode 110 is a semi-transmissive electrode or areflective electrode, as a material to form the first electrode 110, atleast one of magnesium (Mg), silver (Ag), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),magnesium-silver (Mg—Ag), and any combination thereof may be used, butembodiments are not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. In someembodiments, the first electrode 110 may have a triple-layered structureof ITO/Ag/ITO, but embodiments are not limited thereto.

Features related to the charge generating unit are described herein.

The light-emitting device may include (m−1) charge generating units,wherein each of the charge generating units may be between the emissionunits from among the m emission units that are adjacent to each other.

In some embodiments, a (m−1)^(th) charge generating unit may be includedbetween an m^(th) emission unit and a (m−1)^(th) emission unit.

For example, when m is 2, a first electrode, a first emission unit, afirst charge generating unit, and a second emission unit may besequentially stacked.

For example, when m is 3, a first electrode, a first emission unit, afirst charge generating unit, a second emission unit, a second chargegenerating unit, and a third emission unit may be sequentially stacked.

For example, when m is 4, a first electrode, a first emission unit, afirst charge generating unit, a second emission unit, a second chargegenerating unit, a third emission unit, a third charge generating unit,and a fourth emission unit may be sequentially stacked. At least one ofthe (m−1) charge generating units may include an n-type chargegenerating layer, a p-type charge generating layer, and a p-type holeinjection layer.

In some embodiments, in the charge generating unit in the number of(m−1), a charge generating unit (m−1)^(th) from a first electrode may beindicated as a (m−1)^(th) charge generating unit.

As illustrated in FIG. 2 , a (m−1)^(th) charge generating unit CGU(m−1)may include a (m−1)^(th) n-type charge generating layer nCGL(m−1), a(m−1)^(th) p-type charge generating layer pCGL(m−1), and a (m−1)^(th)p-type hole injection layer pHIL(m−1).

In the (m−1)^(th) charge generating unit CGU(m−1), the (m−1)^(th) n-typecharge generating layer nCGL(m−1), the (m−1)^(th) p-type chargegenerating layer pCGL(m−1), and the (m−1)^(th) p-type hole injectionlayer pHIL(m−1) may be stacked sequentially in this stated order.

In some embodiments, the (m−1)^(th) p-type charge generating layerpCGL(m−1) may be in direct contact with the (m−1)^(th) n-type chargetransport layer nCGL(m−1) and the (m−1)^(th) p-type hole injection layerpHIL(m−1).

In the present specification, each element included in the (m−1)^(th)charge generating unit may be understood by referring to the descriptionof each element included in the charge generating unit and not limitedto the “(m−1)^(th)” charge generating unit. For example, description ofthe “(m−1)^(th) n-type charge generating layer” may be understood byreferring to the description of the “n-type charge generating layer”.

Embodiments include an n-type charge generating layer as describedherein.

The n-type charge generating layer may include an n-type organiccompound and a metal material.

In some embodiments, the n-type organic compound may be aphenanthrene-based compound or a phosphine oxide-based compound.

In some embodiments, the n-type organic compound may be selected fromCompounds N1, N2, and N3, and a similar phenanthroline-based compound:

In one or more embodiments, the n-type organic compound may beunderstood by referring to the description of the electron transportingorganic compound provided herein.

The metal material may include at least one selected from an alkalimetal, an alloy of an alkali metal, an alkaline earth metal, an alloy ofan alkaline earth metal, a lanthanide metal, and an alloy of alanthanide metal.

In some embodiments, the metal material may include at least oneselected from lithium (Li), sodium (Na), a Bi—Li alloy, a Bi—Na alloy,ytterbium (Yb), samarium (Sm), europium (Eu), terbium (Tb), holmium(Ho), and dysprosium (Dy).

In some embodiments, a binding energy between the n-type organiccompound and the metal material included in the n-type charge generatinglayer may be 1.2 eV or higher, for example, 1.25 eV or higher. In someembodiments, a binding energy between the n-type organic compound andthe metal material may be about 1.25 eV or higher and about 5 eV orless.

In some embodiments, a volume ratio of the n-type organic compound tothe metal material included in the n-type charge generating layer may bein a range of about 99.9:0.1 to about 80:20.

The binding energy value may be obtained, for example, by simulationusing Gaussian 0.9 B0.1.

As a binding energy between the n-type organic compound and the metalmaterial in the n-type charge generating layer is high, in thelight-emitting device, charge flow may be facilitated, and an increasein driving voltage over time may be prevented.

In some embodiments, the metal material may be an alkali metal or analloy of an alkali metal, and the n-type charge generating layer mayfurther include bismuth (Bi).

In some embodiments, the metal material may be an alloy of an alkalimetal and bismuth (Bi).

In some embodiments, the metal material may be lithium (Li), sodium(Na), a Bi—Li alloy, or a Bi—Na alloy.

When the n-type charge-generating layer is configured to include analkali metal, the alkali metal may be oxidized during a process, therebyincreasing a melting point, and thus a process temperature may beincreased. In this light, as described above, because an alloy of analkali metal and bismuth (Bi) is used as the metal material, the n-typecharge generating layer may be stable. In addition, the alloy of analkali metal and bismuth (Bi) may have a lower melting point, and theefficiency of the process using it may be increased.

In some embodiments, the metal material may be ytterbium (Yb), samarium(Sm), europium (Eu), terbium (Tb), holmium (Ho), or dysprosium (Dy).

The thickness of the n-type charge-generating layer may be in a range ofabout 0.1 nanometers (nm) to about 20 nm.

In some embodiments, the n-type charge generating layer may be in directcontact with an electron transport region of the adjacent emission unit.In some embodiments, a (m−1)^(th) n-type charge generating layernCGL(m−1) included in a (m−1)^(th) charge generating unit CGU(m−1) maybe in direct contact with an electron injection layer or an electrontransport layer included in a (m−1)^(th) emission unit ELU(m−1).

Embodiments including the p-type charge generating layer and the p-typehole injection layer are described herein.

The p-type charge generating layer and the p-type hole injection layermay each independently include an inorganic semiconductor material.

In some embodiments, the inorganic semiconductor material may include apost-transition metal, a halide of a transition metal, a halide of apost-transition metal, bismuth, tellurium, a telluride of a transitionmetal, a telluride of a post-transition metal, a sulfide of a transitionmetal, a sulfide of a post-transition metal, a selenide of a transitionmetal, a selenide of a post-transition metal, or any combinationthereof.

In a light-emitting device according to one or more embodiments, acharge generating unit may include a p-type charge generating layer anda p-type hole injection layer, and the p-type charge generating layerand the p-type hole injection layer may each independently include aninorganic semiconductor material. Accordingly, the p-type hole injectionlayer may serve to regulate the energy level at an interface between acharge generating unit and an emission unit such that charge generationand migration from the p-type charge generating layer to an adjacentemission unit may be facilitated, and in addition, deterioration ofmaterials may be prevented at the interface, thereby preventing anincrease in the driving voltage. Therefore, the light-emitting devicemay provide improved lifespan and/or luminance.

In some embodiments, the inorganic semiconductor material may includeBi, Te, AgI, CuI, NiI₂, CoI₂, PbI₂, SnI₂, AlI₃, GaI₃, InI₃, TiI₃, BiF₃,BiCl₃, BiBr₃, BiI₃, Bi₂S₃, Bi₂Se₃, Bi₂Te₃, or a combination thereof.

In some embodiments, an inorganic semiconductor material included in thep-type charge generating layer may be substantially identical to aninorganic semiconductor material included in the p-type hole injectionlayer.

In some embodiments, an inorganic semiconductor material included in thep-type charge generating layer may be different from an inorganicsemiconductor material included in the p-type hole injection layer.

In some embodiments, the p-type charge generating layer may include, asan inorganic semiconductor material, a post-transition metal, tellurium,a halide of a post-transition metal, a sulfide of a post-transitionmetal, a selenide of a post-transition metal, a telluride of apost-transition metal, or a combination thereof.

In some embodiments, the p-type charge generating layer may include, asan inorganic semiconductor material, bismuth, tellurium, a halide ofbismuth, a sulfide of bismuth, a selenide of bismuth, a telluride ofbismuth, or a combination thereof.

In some embodiments, the p-type charge generating layer may include Bi,Te, BiF₃, BiCl₃, BiBr₃, BiI₃, Bi₂S₃, Bi₂Se₃, Bi₂Te₃, or a combinationthereof.

In some embodiments, the p-type hole injection layer may include, as aninorganic semiconductor material, a halide of a transition metal, forexample, an iodide of a transition metal.

In some embodiments, the p-type hole injection layer may include CuI.

In some embodiments, the p-type charge generating layer and the p-typehole injection layer may each independently further include a holetransporting organic compound. The hole transporting organic compoundmay be understood by referring to the description thereof providedherein.

A hole transporting organic compound included in the p-type chargegenerating layer may be substantially identical to a hole transportingorganic compound included in the p-type hole injection layer. In someembodiments, a hole transporting organic compound included in the p-typecharge generating layer may be different from a hole transportingorganic compound included in the p-type hole injection layer.

In some embodiments, a volume of the hole transporting organic compoundmay be the same as or greater than that of the inorganic semiconductormaterial in the p-type charge generating layer and the inorganicsemiconductor material in the p-type hole injection layer.

In some embodiments, in the p-type charge generating layer, a volumeratio of the hole transporting organic compound to the inorganicsemiconductor material may be in a range of about 99.9:0.1 to about70:30, for example, about 99:1 to about 80:20.

In some embodiments, in the p-type hole injection layer, a volume ratioof the hole transporting organic compound to the inorganic semiconductormaterial may be in a range of about 99.9:0.1 to about 70:30, forexample, about 99:1 to about 80:20.

A volume ratio of the hole transporting organic compound to theinorganic semiconductor material may be determined according to adeposition rate of each material when manufacturing a light-emittingdevice. In addition, a volume ratio of the hole transporting organiccompound to the inorganic semiconductor material in a light-emittingdevice may be obtained by measuring and calculating a weight of eachelement.

The thickness of the p-type charge generating layer and the p-type holeinjection layer may be in a range of about 0.1 nm to about 20 nm.

Embodiments including an emission unit are described herein.

According to embodiments, m emission units may be disposed on the firstelectrode 110.

In some embodiments, among the m emission units, an emission unit m^(th)closest to the first electrode may be indicated as an m^(th) emissionunit ELU(m).

In some embodiments, among the m emission units, an emission unitclosest to the first electrode 110 may be indicated as a first emissionunit ELU(1), an emission unit farthest from the first electrode 110 maybe indicated as an m^(th) emission unit ELU(m), and the first emissionunit ELU(1) to the m^(th) emission unit ELU(m) may be sequentiallyarranged. That is, an (m−1)^(th) charge generating unit CGU(m−1) may bebetween the first emission unit ELU(1) and the m^(th) emission unitELU(m).

As illustrated in FIGS. 3 and 4 , in a light-emitting device accordingto one or more embodiments, a m^(th) emission unit ELU(m) that may bem^(th) from the first electrode 110 among the m emission units mayinclude a m^(th) hole transport region HT(m), a m^(th) emission layerEML(m), and a m^(th) electron transport region ET(m).

In the present specification, description of the m^(th) emission unitmay be understood by referring to the description of the emission unitand not limited to the m^(th) emission unit. For example, descriptionsof the “m^(th) emission layer” may be understood by referring to thedescription of the “emission layer” provided herein unless otherwisestated.

The hole transport region may include a hole injection layer, a holetransport layer, an electron blocking layer, or any combination thereof,and the electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

As illustrated in FIG. 4 , in some embodiments, a light-emitting devicemay include: the first electrode 110 that may be an anode; the secondelectrode 190 that may be a cathode; an m^(th) emission unit ELU(m)between the first electrode 110 and the second electrode 190; a(m−1)^(th) emission unit ELU(m−1) between the first electrode 110 andthe m^(th) emission unit ELU(m); and a (m−1)^(th) charge generating unitCGU(m−1) between the m^(th) emission unit ELU(m) and the (m−1)^(th)emission unit ELU(m−1), wherein the m^(th) emission unit ELU(m) mayinclude an m^(th) emission layer EML(m), the (m−1)^(th) emission unitELU(m−1) may include a (m−1)^(th) emission layer EML(m−1), the(m−1)^(th) emission unit ELU(m−1) may further include a (m−1)^(th) holetransport region HT(m−1) between the first electrode 110 and the(m−1)^(th) emission layer EML(m−1); and a (m−1)^(th) electron transportregion ET(m−1) between the m^(th) emission layer EML(m) and the(m−1)^(th) charge generating unit CGU(m−1), and the m^(th) emission unitELU(m) may include an m^(th) hole transport region HT(m) between the(m−1)^(th) charge generating unit CGU(m−1) and the m^(th) emission layerEML(m); and an m^(th) electron transport region ET(m) between the m^(th)emission layer EML(m) and the second electrode 190, wherein the holetransport regions HT(m−1) and HT(m) may each include a hole injectionlayer, a hole transport layer, an electron blocking layer, or anycombination thereof, and the electron transport regions ET(m−1) andET(m) may each include a hole blocking layer, an electron transportlayer, an electron injection layer, or any combination thereof.

Embodiments including a hole transport region are described herein.

The light-emitting device may include a hole transport region in directcontact with the first electrode or the (m−1)^(th) charge generatingunit. The hole transport region may include a hole transporting organiccompound.

In the present specification, the term “hole transporting organiccompound” refers to any organic material having hole transportability.

In some embodiments, the hole transporting organic compound may includeat least one selected from m-MTDATA, TDATA, 2-TNATA, NPB (NPD), β-TPD, aspiro-TPD, a spiro-NPB, methylated-NPB, TAPC, HMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201, and a compound represented by Formula 202:

wherein, in Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedheterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In some embodiments, in Formula 202, R₂₀₁ and R₂₀₂ may optionally bebound via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be bound viaa single bond, a dimethyl-methylene group, or a diphenyl-methylenegroup.

In some embodiments, in Formula 201 and 202, L₂₀₁ to L₂₀₅ may eachindependently be selected from: a phenylene group, a pentalenylenegroup, an indenylene group, a naphthylene group, an azulenylene group, aheptalenylene group, an indacenylene group, an acenaphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, a pentaphenylene group, a hexacenylene group, a pentacenylenegroup, a rubicenylene group, a coronenylene group, an ovalenylene group,a thiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group.

L₂₀₁ to L₂₀₅ may also each independently be selected from a phenylenegroup, a pentalenylene group, an indenylene group, a naphthylene group,an azulenylene group, a heptalenylene group, an indacenylene group, anacenaphthylene group, a fluorenylene group, a spiro-bifluorenylenegroup, a benzofluorenylene group, a dibenzofluorenylene group, aphenalenylene group, a phenanthrenylene group, an anthracenylene group,a fluoranthenylene group, a triphenylenylene group, a pyrenylene group,a chrysenylene group, a naphthacenylene group, a picenylene group, aperylenylene group, a pentaphenylene group, a hexacenylene group, apentacenylene group, a rubicenylene group, a coronenylene group, anovalenylene group, a thiophenylene group, a furanylene group, acarbazolylene group, an indolylene group, an isoindolylene group, abenzofuranylene group, a benzothiophenylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In some embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In some embodiments, xa5 may be 1, 2, 3, or 4.

In some embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently beselected from a phenyl group, a biphenyl group, a terphenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may also each independently be a phenyl group, abiphenyl group, a terphenyl group, a pentalenyl group, an indenyl group,a naphthyl group, an azulenyl group, a heptalenyl group, an indacenylgroup, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a rubicenyl group, acoronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group,a carbazolyl group, an indolyl group, an isoindolyl group, abenzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, and a pyridinyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a pentalenyl group, anindenyl group, a naphthyl group, an azulenyl group, a heptalenyl group,an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may respectively be understood by referring to thedescriptions of Q₃₁ to Q₃₃ provided herein.

In some embodiments, in Formula 201, at least one selected from R₂₀₁ toR₂₀₃ may each independently be selected from a fluorenyl group, aspiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, anda dibenzothiophenyl group; and a fluorenyl group, a spiro-bifluorenylgroup, a carbazolyl group, a dibenzofuranyl group, and adibenzothiophenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group,a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl groupsubstituted with —F, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, anda dibenzothiophenyl group, but embodiments are not limited thereto.

In some embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be bound via asingle bond, and/or ii) R₂₀₃ and R₂₀₄ may be bound via a single bond.

In some embodiments, in Formula 202, at least one selected from R₂₀₁ toR₂₀₄ may be selected from a carbazolyl group; and a carbazolyl groupsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptylgroup, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, abiphenyl group, a terphenyl group, a phenyl group substituted with aC₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group,a dibenzofuranyl group, and a dibenzothiophenyl group, but embodimentsare not limited thereto.

The compound represented by Formula 201 may be represented by Formula201A:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201A(1), but embodiments are not limited thereto:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201A-1, but embodiments are not limited thereto:

In some embodiments, the compound represented by Formula 202 may berepresented by Formula 202A:

In some embodiments, the compound represented by Formula 202 may berepresented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1, L₂₀₁ to L₂₀₃, xa1to xa3, xa5, and R₂₀₂ to R₂₀₄ may respectively be understood byreferring to the descriptions of L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂to R₂₀₄ provided herein,

R₂₁₁ and R₂₁₂ may each be understood by referring to the description ofR₂₀₃ provided herein, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT39, but embodiments are not limited thereto:

Hole Injection Layer in Hole Transport Region

In some embodiments, a hole transport region included in an emissionunit of the light-emitting device may include a hole injection layer.

In some embodiments, the hole injection layer may be understood byreferring to the description of the p-type hole injection layer. In someembodiments, the hole injection layer may include an inorganicsemiconductor material. Description of the inorganic semiconductormaterial may be understood by referring to the description of theinorganic semiconductor material provided herein.

In some embodiments, the inorganic semiconductor material included inthe hole injection layer may be substantially identical to the inorganicsemiconductor material included in the p-type hole injection layer. Insome embodiments, the inorganic semiconductor material included in thehole injection layer may be different from the inorganic semiconductormaterial included in the p-type hole injection layer.

In some embodiments, the hole injection layer may further include a holetransporting organic compound.

In some embodiments, the hole injection layer may consist of theinorganic semiconductor material and the hole transporting organiccompound.

In some embodiments, the hole injection layer may include a materialsubstantially the same as that included in the p-type hole injectionlayer. In some embodiments, the hole injection layer may include aninorganic semiconductor material and/or a hole transporting organiccompound independently from the p-type hole injection layer.

As illustrated in FIGS. 3 and 4 , the (m−1)^(th) hole transport regionHT(m−1) may include a (m−1)^(th) hole injection layer, and the(m−1)^(th) hole injection layer may be adjacent to at least one of thefirst electrode 110 and the (m−1)^(th) charge generating unit CGU(m−1)and may include an inorganic semiconductor material.

In addition, in some embodiments, the (m−1)^(th) hole injection layermay be in direct contact with the first electrode 110. For example, thefirst hole transport region HT(1) included in the first emission unitELU(1) may include a first hole injection layer, wherein the first holeinjection layer may be adjacent to the first electrode 110 and includean inorganic semiconductor material.

In a light-emitting device according to one or more embodiments, thehole injection layer may include a semiconductor material, therebyfacilitating charge generation and migration at an interface with afirst electrode or a charge generating unit and preventing deteriorationof materials at interfaces between each of the layers and an increase indriving voltage. Therefore, the light-emitting device may provideimproved lifespan and/or luminance.

The thickness of the hole injection layer may be in a range of about 0.1nm to about 20 nm, for example, about 0.1 nm to about 10 nm. When thethickness of hole injection layer is within one of these ranges,satisfactory hole injection characteristics may be obtained without asubstantial increase in the driving voltage.

Embodiments including a hole transport layer in hole transport regionare described herein.

An emission unit in the light-emitting device may include a holetransport layer in direct contact with the emission layer.

The hole transport layer may include at least one selected from holetransporting organic compounds.

In some embodiments, the hole transport layer may include a halide of analkali metal, a halide of an alkaline earth metal, a halide of alanthanide metal, or any combination thereof.

As illustrated in FIGS. 3 and 4 , the m^(th) hole transport region HT(m)may include a m^(th) hole transport layer adjacent to the m^(th)emission layer EML(m), and the m^(th) hole transport layer may include ahole transporting organic compound.

In some embodiments, the m^(th) hole transport layer may include ahalide of an alkali metal, a halide of an alkaline earth metal, a halideof a lanthanide metal, or any combination thereof.

The hole transporting organic compound may be 50 parts by volume orgreater, based on 100 parts by volume of the hole transport layer. Insome embodiments, the hole transporting organic compound in the holetransport layer may be included in a range of about 50 parts by volumeto about 99.9 parts by volume.

The thickness of the hole transport layer may be in a range of about 0.1nm to about 10 nm. When the thickness of hole injection layer is withinany of these ranges, satisfactory hole transporting characteristics maybe obtained without a substantial increase in the driving voltage.

Embodiments including a charge-generating material in a hole transportregion are described herein.

The hole transport region may include a charge generating material aswell as the aforementioned materials, to improve conductive propertiesof the hole transport region. The charge generating material may besubstantially homogeneously or non-homogeneously dispersed in the holetransport region. In some embodiments, the charge-generating materialmay be included in a layer other than a hole injection layer in the holetransport region.

The charge generating material may include, for example, a p-dopant.

In an embodiment, a lowest unoccupied molecular orbital (LUMO) energylevel of the p-dopant may be −3.5 eV or less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butembodiments are not limited thereto.

In some embodiments, the p-dopant may be selected from a quinonederivative, such as tetracyanoquinodimethane (TCNQ) or2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ); a metaloxide, such as tungsten oxide or molybdenum oxide;1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and acompound represented by Formula 221, but embodiments are not limitedthereto:

wherein, in Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may include at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

Embodiments including an emission layer are described herein.

Although not illustrated in FIG. 1 , the emission units may each includean emission layer. In some embodiments, each of the emission units mayinclude one emission layer.

A plurality of emission layers may emit colors of light that aredifferent from or substantially identical to each other. For example,each of the plurality of emission layers may emit blue light, butembodiments are not limited thereto.

The emission layer may include at least one selected from an organiccompound and a semiconductor compound, but compounds to be included inthe emission layer are not limited thereto. Particularly, when theemission layer includes an organic compound, the light-emitting devicemay be referred to as an organic light-emitting device.

In detail, the organic compound may include a host and a dopant.

In detail, the semiconductor compound may be a quantum dot, and in thisembodiment, the light-emitting device may be a quantum dotlight-emitting device.

In some embodiments, the semiconductor compound may be an organicperovskite and/or an inorganic perovskite.

The thickness of the emission layer may be in a range of about 0.1 nm toabout 100 nm. In detail, the thickness of the emission layer may be in arange of about 15 nm to about 50 nm. In detail, when the emission layeremits blue light, the thickness of the blue emission layer may be in arange of about 15 nm to about 20 nm, when the emission layer emits greenlight, the thickness of the green emission layer may be in a range ofabout 20 nm to about 40 nm, and when the emission layer emits red light,the thickness of the red emission layer may be in a range of about 40 nmto about 50 nm. When the thickness of the emission layer is within anyof these ranges, the light-emitting device may have excellentluminescence characteristics without a substantial increase in drivingvoltage.

The emission layer in the organic light-emitting device may include ahost and a dopant. The dopant may be a phosphorescent dopant, afluorescent dopant, a delayed fluorescent dopant, or any combinationthereof.

The amount of the dopant in the emission layer may be, in general, in arange of about 0.01 parts to about 15 parts by weight based on 100 partsby weight of the host, but embodiments are not limited thereto.

The host may include a compound represented by Formula 301:

Formula 301 reads:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21), wherein, in Formula 301,

Ar₃₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group and a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), and

xb21 may be an integer from 1 to 5,

wherein Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments are not limitedthereto.

In some embodiments, in Formula 301, Ar₃₀₁ may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments are not limitedthereto.

When xb11 in Formula 301 is 2 or greater, at least two Ar₃₀₁(s) may bebound via a single bond.

In one or more embodiments, the compound represented by Formula 301 maybe represented by Formula 301-1 or 301-2:

wherein, in Formulae 301-1 and 301-2,

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene group, anaphthalene group, a phenanthrene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a pyridine group,a pyrimidine group, an indene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,an indole group, a carbazole group, a benzocarbazole group, adibenzocarbazole group, a furan group, a benzofuran group, adibenzofuran group, a naphthofuran group, a benzonaphthofuran group, adinaphthofuran group, a thiophene group, a benzothiophene group, adibenzothiophene group, a naphthothiophene group, a benzonapthothiophenegroup, and a dinaphthothiophene group,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may respectively be understood byreferring to the descriptions of L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃provided herein,

L₃₀₂ to L₃₀₄ may each be understood by referring to the description ofL₃₀₁ provided herein,

xb2 to xb4 may each be understood by referring to the descriptions ofxb1 provided herein, and

R₃₀₂ to R₃₀₄ may each be understood by referring to the description ofR₃₀₁ provided herein.

In some embodiments, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ mayeach independently be selected from: a phenylene group, a naphthylenegroup, a fluorenylene group, a spiro-bifluorenylene group, abenzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, aperylenylene group, a pentaphenylene group, a hexacenylene group, apentacenylene group, a thiophenylene group, a furanylene group, acarbazolylene group, an indolylene group, an isoindolylene group, abenzofuranylene group, a benzothiophenylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group.

L₃₀₁ to L₃₀₄ may also be selected from: a phenylene group, a naphthylenegroup, a fluorenylene group, a spiro-bifluorenylene group, abenzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, aperylenylene group, a pentaphenylene group, a hexacenylene group, apentacenylene group, a thiophenylene group, a furanylene group, acarbazolylene group, an indolylene group, an isoindolylene group, abenzofuranylene group, a benzothiophenylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ may respectivelybe understood by referring to the descriptions of Q₃₁ to Q₃₃ providedherein.

In some embodiments, in Formulae 301, 301-1, and 301-2, R₃₀₁ to R₃₀₄ mayeach independently be selected from: a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, and an imidazopyrimidinyl group, and anazacarbazolyl group.

R₃₀₁ to R₃₀₄ may also be selected from a phenyl group, a biphenyl group,a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ may respectivelybe understood by referring to the descriptions of Q₃₁ to Q₃₃ providedherein.

In some embodiments, the host may include an alkaline earth metalcomplex. For example, the host may include a beryllium (Be) complex,e.g., Compound H55, a magnesium (Mg) complex, or a zinc (Zn) complex.

The host may include at least one selected from9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55,but embodiments are not limited thereto:

In some embodiments, the host may include at least one selected from asilicon-containing compound (e.g., BCPDS or the like) and a phosphineoxide-containing compound (e.g., POPCPA or the like).

The host may include one type of compounds only or two or more differenttypes of compounds (for example, BCPDS and POPCPA). As such, embodimentsmay be modified in various ways.

The phosphorescent dopant may include an organometallic complexrepresented by Formula 401:

Formula 401

M(L₄₀₁)_(xcl)(L₄₀₂)_(xc2)

wherein, in Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd),osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁ may be selected from ligands represented by Formula 402, and xc1may be 1, 2, or 3, and when xc1 is 2 or greater, at least two L₄₀₁(s)may be substantially identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer selected from 0to 4, and when xc2 is 2 or greater, at least two L₄₀₂(s) may besubstantially identical to or different from each other,

X₄₀₁ to X₄₀₄ may each independently be a nitrogen or a carbon,

X₄₀₁ and X₄₀₃ may be bound to each other via a single bond or a doublebond, X₄₀₂ and X₄₀₄ may be bound to each other via a single bond or adouble bond,

A₄₀₁ and A₄₀₂ may each independently be a C₅-C₆₀ carbocyclic group or aC₁-C₆₀ heterocyclic group,

X₄₀₅ may be selected from a single bond, *—O—*′, *—S—*′, *—C(═O)—*′,*—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′,and *═C═*′, wherein Q₄₁₁ and Q₄₁₂ may be selected from hydrogen,deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group,a biphenyl group, a terphenyl group, and a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₂₀ alkyl group, a substituted orunsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂),—B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂),wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group, and a C₁-C₂₀heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In an embodiment, in Formula 402, A₄₀₁ and A₄₀₂ may each independentlybe selected from a benzene group, a naphthalene group, a fluorene group,a spiro-bifluorene group, an indene group, a pyrrole group, a thiophenegroup, a furan group, an imidazole group, a pyrazole group, a thiazolegroup, an isothiazole group, an oxazole group, an isoxazole group, apyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a quinoxaline group, a quinazoline group, a carbazole group, abenzimidazole group, a benzofuran group, a benzothiophene group, anisobenzothiophene group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, andX₄₀₂ may be carbon, or ii) X₄₀₁ and X₄₀₂ may both be nitrogen.

In some embodiments, in Formula 402, R₄₀₁ and R₄₀₂ may eachindependently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group,a cyclohexyl group, an adamantyl group, a norbornanyl group, and anorbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantyl group, anorbornanyl group, a norbornenyl group a phenyl group, a biphenyl group,a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornanylgroup, a norbornenyl group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and adibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁),—S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ may eachindependently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a biphenyl group, and a naphthyl group, butembodiments are not limited thereto.

In one or more embodiments, when xc1 in Formula 401 is 2 or greater, twoA₄₀₁(s) of at least two L₄₀₁(s) may optionally be bound via X₄₀₇ as alinking group, or two A₄₀₂(s) may optionally be bound via X₄₀₈ as alinking group (see Compounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may eachindependently be selected from a single bond, *—O—*′, *—S—*′,*—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, and *—C(Q₄₁₃)═C(Q₄₁₄)-*′,wherein Q₄₁₃ and Q₄₁₄ may each independently be hydrogen, deuterium, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenylgroup, a terphenyl group, or a naphthyl group, but embodiments are notlimited thereto.

L₄₀₂ in Formula 401 may be any suitable monovalent, divalent, ortrivalent organic ligand. For example, L₄₀₂ may be selected fromhalogen, diketone (e.g., acetylacetonate), a carboxylic acid (e.g.,picolinate), —C(═O), isonitrile, —CN, and phosphorus-containingsubstance (e.g., phosphine or phosphite), but embodiments are notlimited thereto.

In some embodiments, the phosphorescent dopant compound may include, forexample, at least one selected from Compounds PD1 to PD25, butembodiments are not limited thereto:

The fluorescent dopant may include an arylamine compound or astyrylamine compound.

In some embodiments, the fluorescent dopant may include a compoundrepresented by Formula 501:

wherein, in Formula 501,

Ar₅₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group and a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstitutedheterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group.

xd1 to xd3 may each independently be an integer from 0 to 3.

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedheterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be an integer from 1 to 6.

In some embodiments, in Formula 501, Ar₅₀₁ may be selected from: anaphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, in Formula 501, L₅₀₁ to L₅₀₃ may eachindependently be selected from: a phenylene group, a naphthylene group,a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and a phenylene group, a naphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexaacetyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group.

In some embodiments, in Formula 501, R₅₀₁ and R₅₀₂ may eachindependently be selected from: a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodimentsare not limited thereto.

In some embodiments, the fluorescent dopant may be selected fromCompounds FD1 to FD22:

In some embodiments, the fluorescent dopant may be selected from thefollowing compounds, but embodiments are not limited thereto:

In some embodiments, the delayed fluorescent dopant may include acompound represented by Formula 502:

wherein, in Formula 502,

A₅₀₁ to A₅₀₃ may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₅ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

a501 to a505 may each independently be an integer from 0 to 3,

R₅₀₃ to R₅₀₇ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ alkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, and

c11 to c13 may each be an integer from 0 to 6.

In some embodiments, in Formula 502, A₅₀₁ to A₅₀₃ may each independentlybe selected from a benzene group, a naphthalene group, a heptalenegroup, a fluorene group, a spiro-bifluorene group, a benzofluorenegroup, a dibenzofluorene group, a phenalene group, a phenanthrene group,an anthracene group, a fluoranthene group, a triphenylene group, apyrene group, a chrysene group, a naphthacene group, a picene group, aperylene group, a pentaphene group, an indenoanthracene group, anindenophenanthrene group, and a group represented by Formula 503:

wherein, in Formula 503,

A₅₀₄ to A₅₀₆ may each be understood by referring to the description ofA₅₀₁ in Formula 502,

L₅₀₄ to L₅₀₈ may each be understood by referring to the description ofL₅₀₁ in Formula 502,

a504 to a508 may each be understood by referring to the description ofa501 in Formula 502,

R₅₀₆ to R₅₁₀ may each be understood by referring to the description ofR₅₀₃ in Formula 502, and

c14 to c16 may each be understood by referring to the description of c11in Formula 502.

In some embodiments, in Formula 502, L₅₀₁ to L₅₀₅ may respectively beunderstood by referring to the descriptions of L₅₀₁ to L₅₀₅ providedherein.

In some embodiments, in Formula 502, R₅₀₃ to R₅₀₇ may each independentlybe selected from:

a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,an n-butyl group, iso-butyl group, a sec-butyl group, a tert-butylgroup, a phenyl group, a biphenyl group, a terphenyl group, a naphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenylgroup, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a thiophenyl group, a furanyl group, acarbazolyl group, an indolyl group, an isoindolyl group, a benzofuranylgroup, a benzothiophenyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, and a pyridinyl group; and

a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,an n-butyl group, iso-butyl group, a sec-butyl group, a tert-butylgroup, a phenyl group, a biphenyl group, a terphenyl group, a naphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenylgroup, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a thiophenyl group, a furanyl group, acarbazolyl group, an indolyl group, an isoindolyl group, a benzofuranylgroup, a benzothiophenyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, and a pyridinyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group.

In one or more embodiments, in Formula 502, c11 to c13 may each be 0 or1, but embodiments are not limited thereto.

In some embodiments, the delayed fluorescent dopant compound may beselected from Compounds FD24 to FD26:

An emission layer of the quantum dot light-emitting device may include aquantum dot. That is, the quantum dot light-emitting device may includea quantum dot emission layer. The quantum dot emission layer may includea plurality of quantum dots (inorganic nanoparticles) arranged in asingle layer or a plurality of layers.

The term “quantum dot” as used herein refers to a crystal of asemiconductor compound and may include any material emitting light ofemission wavelengths of different lengths according to the size of thecrystal. Accordingly, types of compounds constituting the quantum dotare not particularly limited.

In some embodiments, the quantum dot may include a semiconductormaterial selected from the group consisting of: a group III-VIsemiconductor compound; a group I-III-VI semiconductor compound; a groupII-VI semiconductor compound; a group III-V semiconductor compound; agroup IV-VI semiconductor compound; a group IV element or compound; andany combination thereof.

In some embodiments, the group III-VI semiconductor compound may beselected from a binary compound such as In₂S₃. The group I-III-VIsemiconductor compound may be selected from a ternary compound such asthe group consisting of AgInS, AgInS₂, CuInS, or CuInS₂, and anycompound thereof, but embodiments are not limited thereto.

The II-VI semiconductor compound may be selected from the groupconsisting of: a binary compound selected from the group consisting ofCdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and amixture thereof; a ternary compound selected from the group consistingof CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe,CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe,MgZnSe, MgZnS, and a mixture thereof; and a quaternary compound selectedfrom the group consisting of CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS,CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and a mixture thereof,but embodiments are not limited thereto.

In some embodiments, the III-V semiconductor compound may be selectedfrom the group consisting of: a binary compound selected from the groupconsisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP,InAs, InSb and a mixture thereof; a ternary compound selected from thegroup consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs,AlNSb, AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb, and amixture thereof; and a quaternary compound selected from the groupconsisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP,GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs,InAlPSb, and a mixture thereof, but embodiments are not limited thereto.

In some embodiments, the IV-VI semiconductor compound may be selectedfrom the group consisting of: a binary compound selected from the groupconsisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and a mixture thereof; aternary compound selected from the group consisting of SnSeS, SnSeTe,SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and a mixturethereof; and a quaternary compound selected from the group consisting ofSnPbSSe, SnPbSeTe, SnPbSTe, and a mixture thereof, but embodiments arenot limited thereto.

For example, the Group IV element or compound may be selected from thegroup consisting of: a single element compound selected from Si, Ge, andany mixture thereof; and a binary compound selected from SiC, SiGe, andany mixture thereof, but embodiments are not limited thereto.

In this embodiment, the binary compound, the ternary compound, or thequaternary compound may be present in particles at a uniformconcentration or in the same particle by being partially divided intodifferent concentrations.

The quantum dot may have uniform single structure or a core-shell doublestructure. In some embodiments, the core-shell may include differentmaterials. For example, materials constituting each of the core and theshell may include different semiconductor compounds.

The shell of the quantum dot may serve as a protective layer configuredto prevent chemical denaturation of the core to maintain semiconductorcharacteristics and/or as a charging layer configured to impartelectrophoretic characteristics to the quantum dot. The shell may bemonolayer or multilayer. An interface between a core and a shell mayhave a concentration gradient where a concentration of elements presentin the shell decreases toward the center.

Examples of the shell of the quantum dot include metal or nonmetaloxide, a semiconductor compound, or a combination thereof. In someembodiments, the metal or nonmetal oxide may include a binary compoundsuch as SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃,Fe₃O₄, CoO, Co₃O₄, or NiO or a ternary compound such as MgAl₂O₄,CoFe₂O₄, NiFe₂O₄, or CoMn₂O₄, but embodiments are not limited thereto.In some embodiments, the semiconductor compound may be CdS, CdSe, CdTe,ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs,InP, InGaP, InSb, AlAs, AlP, or AlSb, but embodiments are not limitedthereto.

The diameter of the quantum dot is not particularly limited. Thediameter may be, for example, in a range of about 1 nm to about 10 nm.By adjusting the size of the quantum dot, the energy band gap may alsobe adjusted, thereby obtaining light of various wavelengths in thequantum dot emission layer. By using quantum dots of various sizes, adisplay that may emit light of various wavelengths may be realized.

In some embodiments, the size of the quantum dot may be selected suchthat the quantum dot may emit red, green, and/or blue light to enablecolor display. In addition, the size of the quantum dot may be selectedsuch that the quantum dot may emit white light by combining variouslight of colors.

In addition, the quantum dot may be specifically, a spherical,pyramidal, multi-arm, or cubic nanoparticle, nanotube, nanowire,nanofiber, or nanoplate particle, but embodiments are not limitedthereto.

The quantum dot may have a full width of half maximum (FWHM) of aspectrum of an emission wavelength of about 45 nm or less, about 40 nmor less, or about 30 nm or less. When the FWHM of the quantum dot iswithin this range, color purity or color reproducibility may beimproved. In addition, because light emitted through the quantum dot isemitted in all directions, an optical viewing angle may be improved.

Quantum dots may be synthesized by a wet chemical process, a metal metalchemical vapor deposition process, a molecular beam epitaxy process, orany similar process.

The wet chemical process is a method of growing a particle crystal byadding a precursor material in an organic solvent. When the crystalgrows, the organic solvent may naturally serve as a dispersantcoordinated on the surface of the quantum dot crystal and control thegrowth of the crystal. Thus, the wet chemical method may be easier thanthe vapor deposition process such as the metal organic chemical vapordeposition (MOCVD) or the molecular beam epitaxy (MBE) process. Further,the growth of inorganic nanoparticles may be controlled with a lowermanufacturing cost.

Electron Transport Region

The light-emitting device may include an electron transport region indirect contact with the second electrode or the charge generating unit.

In some embodiments, the electron transport region may include aninorganic insulating material.

In an embodiment, the inorganic insulating material may include a halideof an alkali metal, a halide of an alkaline earth metal, or anycombination thereof.

In some embodiments, the inorganic insulating material may be a compoundhaving a wide band gap of about 7 eV or greater. Accordingly, theinorganic insulating material may not substantially absorb light.

In addition, in some embodiments, the electron transport region mayfurther include a metal dopant to be doped in the inorganic insulatingmaterial. The metal dopant, for example, may include at least oneselected from an alkali metal, an alloy of an alkali metal, an alkalineearth metal, an alloy of an alkaline earth metal, a lanthanide metal,and an alloy of a lanthanide metal.

In some embodiments, the inorganic insulating material may berepresented by Formula X, and the metal dopant may be represented byFormula Y:A_(n1)B_(m1)  Formula XC  Formula Y

wherein, in Formulae X and Y,

A and C may each independently include an alkali metal, an alkalineearth metal, a lanthanide metal, or any combination thereof,

B may be halogen,

n1 and m1 may each independently be an integer of 1 or greater such thata material of Formula X may be electrically neutral, and

A and C may be different from each other.

For example, in Formulae X and Y, A may include Li, Na, K, Rb, Cs, orany combination thereof, B may include F, Cl, Br, I, or any combinationthereof, n1 and m1 may each be 1, and C may be La, Ce, Pr, Nd, Pm, Sm,Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or any combination thereof.

In some embodiments, the inorganic insulating material may include NaI,KI, RbI, CsI, NaCl, KCl, RbCl, CsCl, NaF, KF, RbF, CsF, or anycombination thereof, and the metal dopant may include Mg, La, Ce, Pr,Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or any combinationthereof.

In some embodiments, the metal dopant may be a compound having a lowwork function of about 2.6 eV or lower.

In some embodiments, the inorganic insulating material may be a compoundhaving a wide band gap of about 7 eV or greater. Accordingly, theinorganic insulating material may not substantially absorb light.

Electron Injection Layer in Electron Transport Region

In some embodiments, an electron transport region included in anemission unit of the light-emitting device may include an electroninjection layer. For example, the electron injection layer may be ann-type electron injection layer.

In some embodiments, the m^(th) electron transport region may include ann-type electron injection layer, and the n-type electron injection layermay include the inorganic insulating material.

In some embodiments, the n-type electron injection layer may consist ofthe inorganic insulating material. In this embodiment, the electroninjection layer may not include a material other than the inorganicinsulating material.

In some embodiments, the n-type electron injection layer may furtherinclude a metal dopant.

In some embodiments, for example, the n-type electron injection layermay consist of the inorganic insulating material and the metal dopant.

In some embodiments, the n-type electron injection layer may be indirect contact with the second electrode. For example, as illustrated inFIGS. 3 and 4 , the m^(th) electron transport region ET(m) may includean n-type electron injection layer, wherein the n-type electroninjection layer may be adjacent to the second electrode 190 and mayinclude an inorganic insulating material.

In some embodiments, the n-type electron injection layer may be indirect contact with the charge generating unit. For example, asillustrated in FIG. 4 , the (m−1)^(th) electron transport region ET(m−1)may include an n-type electron injection layer, wherein the n-typeelectron injection layer may be in direct contact with the (m−1)^(th)charge generating unit CGU(m−1) and may include an inorganic insulatingmaterial.

In a light-emitting device according to one or more embodiments, then-type electron injection layer may consist of an inorganic compound andnot include an organic material, thereby facilitating charge generationand migration at an interface with a second electrode or a chargegenerating unit and preventing deterioration of materials at interfacesbetween each of the layers and an increase in driving voltage.Therefore, the light-emitting device may provide improved lifespanand/or luminance.

The volume of the inorganic insulating material in the electrontransport region may be equal to or greater than the volume of the metaldopant. In some embodiments, the volume of the metal dopant may be in arange of about 0 parts by volume to about 40 parts by volume, based on100 parts by volume of the electron injection layer.

In some embodiments, a volume ratio of the inorganic insulating materialto the metal dopant may be in a range of about 100:0 to about 70:30.When the volume ratio is within this range, optical absorption by anarrow band gap of the inorganic insulating material may be complementedby the metal dopant.

The thickness of the n-type electron injection layer may be in a rangeof about 0.1 nm to about 5 nm. When the thickness of n-type electroninjection layer is within this range, satisfactory electron injectioncharacteristics may be obtained without a substantial increase in thedriving voltage.

Electron Transport Layer in Electron Transport Region

The light-emitting device may further include an electron transportlayer in an electron transport region of the emission unit. In someembodiments, the light-emitting device may include an electron transportlayer that is in direct contact with the emission layer.

The electron transport layer may include at least one selected fromelectron transporting organic compounds.

In some embodiments, the electron transport layer may include a halideof an alkali metal, a halide of an alkaline earth metal, a halide of alanthanide metal, or any combination thereof.

In some embodiments, as illustrated in FIGS. 3 and 4 , the m^(th)electron transport region ET(m) may include a m^(th) electron transportlayer adjacent to the m^(th) emission layer EML(m), and the m^(th)electron transport layer may include an electron transporting organiccompound.

In some embodiments, the electron transport layer may further include ahalide of an alkali metal, a halide of an alkaline earth metal, a halideof a lanthanide metal, an organic complex of an alkali metal, an organiccomplex of an alkaline earth metal, an organic complex of a lanthanidemetal, or any combination thereof.

In the present specification, the “electron transporting organiccompound” refers to a metal-free compound including at least one πelectron-depleted nitrogen-containing ring

The term “π electron-depleted nitrogen-containing ring” as used hereinrefers to a C₁-C₆₀ heterocyclic group having at least one *—N═*′ moietyas a ring-forming moiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N═*′ moiety, ii) a heteropolycyclic group in which at least two5-membered to 7-membered heteromonocyclic groups, each having at leastone *—N═*′ moiety, are condensed, or iii) a heteropolycyclic group inwhich at least one of a 5-membered to 7-membered heteromonocyclic group,each having at least one *—N═*′ moiety, is condensed with at least oneC₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring may includeimidazole, pyrazole, thiazole, isothiazole, oxazole, isoxazole,pyridine, pyrazine, pyrimidine, pyridazine, indazole, purine, quinoline,isoquinoline, benzoquinoline, phthalazine, naphthyridine, quinoxaline,quinazoline, cinnoline, phenanthridine, acridine, phenanthroline,phenazine, benzimidazole, isobenzothiazole, benzoxazole, isobenzoxazole,triazole, tetrazole, oxadiazole, triazine, thiadiazole, imidazopyridine,imidazopyrimidine, and azacarbazole, but embodiments are not limitedthereto.

In the present specification, in detail, the “electron transportingorganic compound” may include a compound represented by Formula 601:[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  Formula 601

wherein, in Formula 601,

Ar₆₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group and a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, aC₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, or a naphthyl group, and

xe21 may be an integer from 1 to 5.

In an embodiment, at least one selected from Ar₆₀₁(s) in the number ofxe11 and R₆₀₁(s) in the number of xe21 may include the πelectron-depleted nitrogen-containing ring.

In some embodiments, in Formula 601, Ar₆₀₁ may be selected from:

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

When xe11 in Formula 601 is 2 or greater, at least two Ar₆₀₁(s) may bebound via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracenegroup.

In one or more embodiments, a compound represented by Formula 601 may berepresented by Formula 601-1:

wherein, in Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be understood by referring to thedescription of L₆₀₁ provided herein,

xe611 to xe613 may each independently be understood by referring to thedescription of xe1 provided herein,

R₆₁₁ to R₆₁₃ may each independently be understood by referring to thedescription of R₆₀₁ provided herein, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In an embodiment, in Formulae 601 and 601-1, L₆₀₁ and L₆₁₁ to L₆₁₃ mayeach independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group, but embodiments are not limitedthereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and601-1 may each independently be 0, 1, or 2.

In one embodiment, in Formulae 601 and 601-1, R₆₀₁ and R₆₁₁ to R₆₁₃ mayeach independently be selected from: a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ and Q₆₀₂ may respectively be understood by referring to thedescriptions of Q₆₀₁ and Q₆₀₂ provided herein.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36, but embodiments are not limited thereto:

In some embodiments, the electron transport region may include at leastone compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ:

In some embodiments, the electron transport layer may further include ametal-containing material.

In some embodiments, the electron transport layer may include theelectron transporting organic compound and the metal-containingmaterial, and the electron transporting organic compound may be includedin an amount of 50 parts by volume or greater, or about 50 parts byvolume to about 99 parts by volume, based on 100 parts by volume of theelectron transport layer.

The thickness of the electron transport layer may be in a range of about0.1 nm to about 10 nm. When the thickness of electron transport layer iswithin this range, satisfactory electron transporting characteristicsmay be obtained without a substantial increase in the driving voltage.

Metal-Containing Material in Electron Transport Region

The electron transport region may further include a material containingmetal, in addition to the materials described above. In someembodiments, the electron transport region may further include ametal-containing material, and the metal-containing material may includeat least one selected from an alkali metal complex and an alkaline earthmetal complex.

Each ligand coordinated with the metal ion of the alkali metal complexand the alkaline earth metal complex may independently be selected fromhydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline,hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole,hydroxyphenylthiazole, hydroxyphenyloxadiazole,hydroxyphenylthiadiazole, hydroxyphenylpyridine,hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine,phenanthroline, and cyclopentadiene, but embodiments are not limitedthereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, e.g., Compound ET-D1 (LiQ) or Compound ET-D2:

Embodiments include a second electrode 190 as described herein.

The second electrode 190 may be on the m^(th) emission unit describedabove. In an embodiment, the second electrode 190 may be a cathode thatis an electron injection electrode. In this embodiment, a materialconfigured to form the second electrode 190 may be a material having alow work function, for example, a metal, an alloy, an electricallyconductive compound, or a combination thereof.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but embodiments are not limited thereto. Thesecond electrode 190 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

The thickness of the second electrode 190 may be in a range of about 5nm to about 20 nm. When the thickness of second electrode 190 is withinthis range, optical absorption in the second electrode 190 may beminimized, and satisfactory electron injection characteristics may beobtained without a substantial increase in the driving voltage.

Various apparatuses may be formed from the materials discussed herein.The light-emitting device described above may be applicable to variousdevices. According to one or more embodiments, a device may include thelight-emitting device.

For example, the apparatus may be a light-emitting apparatus, anauthentication apparatus, or an electronic apparatus, but embodimentsare not limited thereto.

Embodiments include an emission apparatus as described herein.

Referring to FIG. 5 , an emission apparatus 3 according to an embodimentwill be described. In the emission apparatus 3, a color filter 340 maybe disposed on at least one traveling direction of light emitted fromthe light-emitting device 1.

In some embodiments, the color filter 340 may be directly bonded to thelight-emitting device via a bonding layer or the like. In someembodiments, the color filter 340 may be spaced apart from thelight-emitting device. For example, a charging layer including aninsulating layer including a transparent material having a transparentproperty or an air layer may be between the color filter 340 and thelight-emitting device.

For example, the emission apparatus 3 may include a first electrode 321,a first emission unit 322, a first charge generating unit (notillustrated), a second emission unit 323, and a second electrode 324. Insome embodiments, the first emission unit 322 and the second emissionunit 323 may each emit blue light, but embodiments are not limitedthereto.

A first substrate 310 of the emission apparatus 3 may include aplurality of sub-pixel areas, and the color filter 340 may include aplurality of color filter areas 341, 342, and 343 respectivelycorresponding to the plurality of sub-pixel areas. A pixel-defining film330 may be disposed between the plurality of sub-pixel areas to defineeach sub-pixel area. The color filter 340 may include light blockingpatterns 344 between the plurality of color filter areas 341, 342, and343.

The plurality of color filter areas 341, 342, and 343 may include afirst color filter area 341 emitting first color light; a second colorfilter area 342 emitting second color light; and a third color filterarea 343 emitting a third color light, and the first color light, thesecond color light, and the third color light may have different maximumemission wavelengths. In some embodiments, the first color light may bered light, the second color light may be green light, and the thirdcolor light may be blue light, but embodiments are not limited thereto.

In some embodiments, the plurality of color filter areas 341, 342, and343 may each include a quantum dot, but embodiments are not limitedthereto. In some embodiments, the first color filter area 341 mayinclude a red quantum dot, the second color filter area 342 may includea green quantum dot, and the third color filter area 343 may not includea quantum dot.

The quantum dot may be understood by referring to the description of thequantum dot provided herein.

The first color filter area 341, the second color filter area 342, andthe third color filter area 343 may each further include a scatterer,but embodiments are not limited thereto.

In some embodiments, the light-emitting device may emit first light, thefirst color filter area 341 may absorb the first light to emit a 1-1color light, the second color filter area 342 may absorb the first lightto emit a 2-1 color light, and the third color filter area 343 mayabsorb the first light to emit a 3-1 color light. In this embodiment,the 1-1 color light, the 2-1 color light, and the 3-1 color light mayeach have a different maximum emission wavelength. In some embodiments,the first light may be blue light, the 1-1 color light may be red light,the 2-1 color light may be green light, and the 3-1 color light may beblue light, but embodiments are not limited thereto.

The emission apparatus may further include a thin-film transistor, inaddition to the light-emitting device. The thin-film transistor mayinclude a source electrode, a drain electrode, and an activation layer,wherein one of the source electrode and the drain electrode may beelectrically connected to one of the first electrode and the secondelectrode of the light-emitting device.

The thin-film transistor may further include a gate electrode, a gateinsulating film, or the like. The activation layer may include acrystalline silicon, an amorphous silicon, an organic semiconductor, andan oxide semiconductor, but embodiments are not limited thereto.

The emission apparatus may further include a sealing portion configuredto seal the light-emitting device. The sealing portion may be disposedbetween the color filter and the light-emitting device. The sealing partmay allow an image from the light-emitting device to be realized and mayblock air from the outside and moisture from penetrating into thelight-emitting device. The sealing portion may be a sealing substrateincluding a transparent glass or a plastic substrate. The sealingportion may be a thin film encapsulating layer including a plurality oforganic layers and/or a plurality of inorganic layers. When the sealingportion is a thin film encapsulating layer, the emission apparatus as awhole may be flexible.

The emission apparatus may be used in various displays, light sources,or the like.

Embodiments include an authentication apparatus as described herein.

The authentication apparatus may be, for example, a biometricauthentication apparatus that identifies an individual according tobiometric information (e.g., a fingertip, a pupil, or the like). Theauthentication apparatus may further include a biometric informationcollecting unit, in addition to the light-emitting device describedabove.

Embodiments include an electronic apparatus as described herein. Theelectronic apparatus may be applicable to a personal computer (e.g., amobile personal computer), a cellphone, a digital camera, an electronicnote, an electronic dictionary, an electronic game console, a medicaldevice (e.g., an electronic thermometer, a blood pressure meter, aglucometer, a pulse measuring device, a pulse wave measuring device, anelectrocardiograph recorder, an ultrasonic diagnosis device, anendoscope display device), a fish finder, various measurement devices,gauges (e.g., gauges of an automobile, an airplane, a ship), aprojector, but embodiments are not limited thereto.

Embodiments include a manufacturing method as described herein. Eachlayer included in the emission units and each layer included in thecharge-generating units may be formed in a certain region by using oneor more suitable methods selected from vacuum deposition, spin coating,casting, Langmuir-blodgett (LB) deposition, ink-jet printing,laser-printing, and laser-induced thermal imaging.

When each layer included in the emission units and each layer includedin the charge-generating units are formed by vacuum deposition, thevacuum deposition may be performed at a deposition temperature in arange of about 100° C. to about 500° C., at a vacuum degree in a rangeof about 10⁻⁸ torr to about 10⁻³ torr, and at a deposition rate in arange of about 0.01 Angstroms per second (Å/sec) to about 100 Å/sec,depending on the material to be included in each layer and the structureof each layer to be formed.

When each layer included in the emission units and each layer includedin the charge-generating units are formed by spin coating, the spincoating may be performed at a coating rate of about 2,000 revolutionsper minute (rpm) to about 5,000 rpm and at a heat treatment temperatureof about 80° C. to about 200° C., depending on the material to beincluded in each layer and the structure of each layer to be formed.

General definitions of substituents may include terms described herein.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic hydrocarbon monovalent group having 1 to 60 carbonatoms. Examples thereof include a methyl group, an ethyl group, a propylgroup, an iso-butyl group, a sec-butyl group, a tert-butyl group, apentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀alkylene group” as used herein refers to a divalent group having thesame structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon double bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group. Examples thereof include anethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group. Examples thereof include anethynyl group and a propynyl group. The term “C₂-C₆₀ alkynylene group”as used herein refers to a divalent group having the same structure asthe C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by -OA₁₀₁ (wherein A₁₀₁ is a C₁-C₆₀ alkyl group).Examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group including 3 to 10 carbon atoms.Examples thereof include a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent monocyclic group including at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms.Examples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone double bond in its ring, and is not aromatic. Examples thereofinclude a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenylgroup. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers toa divalent group having the same structure as the C₃-C₁₀ cycloalkenylgroup.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group including at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one double bond in its ring. Examples of the C₁-C₁₀heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolylgroup, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group.The term “C₁-C₁₀ heterocycloalkenylene group” as used herein refers to adivalent group having the same structure as the C₁-C₁₀heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 6 carbon atoms. Theterm “C₆-C₆₀ arylene group” as used herein refers to a divalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms.Examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthylgroup, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, anda chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylenegroup each independently include two or more rings, the respective ringsmay be fused.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system having at least oneheteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used hereinrefers to a divalent group having a heterocyclic aromatic system havingat least one heteroatom selected from N, O, Si, P, and S as aring-forming atom and 1 to 60 carbon atoms. Examples of the C₁-C₆₀heteroaryl group include a pyridinyl group, a pyrimidinyl group, apyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinylgroup, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group andthe C₁-C₆₀ heteroarylene group each independently include two or morerings, the respective rings may be fused.

The term “C₆-C₆₀ aryloxy group” as used herein is represented by -OA₁₀₂(wherein A₁₀₂ is the C₆-C₆₀ aryl group). The term “C₆-C₆₀ arylthiogroup” as used herein is represented by -SA₁₀₃ (wherein A₁₀₃ is theC₆-C₆₀ aryl group).

The term “C₁-C₆₀ heteroaryloxy group” as used herein indicates -OA₁₀₄(wherein A₁₀₄ is a C₁-C₆₀ heteroaryl group). The term “C₁-C₆₀heteroarylthio group” as used herein indicates -SA₁₀₅ (wherein A₁₀₅ is aC₁-C₆₀ heteroaryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group that has two or more rings condensedand only carbon atoms as ring forming atoms (e.g., 8 to 60 carbonatoms), wherein the entire molecular structure is non-aromatic. Examplesof the monovalent non-aromatic condensed polycyclic group may include afluorenyl group. The term “divalent non-aromatic condensed polycyclicgroup” as used herein refers to a divalent group having substantiallythe same structure as the monovalent non-aromatic condensed polycyclicgroup.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group that has two or more condensedrings and at least one heteroatom selected from N, O, Si, P, and S, inaddition to carbon atoms (e.g., 1 to 60 carbon atoms), as a ring-formingatom, wherein the entire molecular structure is non-aromatic. Examplesof the monovalent non-aromatic condensed heteropolycyclic group mayinclude a carbazolyl group. The term “divalent non-aromatic condensedheteropolycyclic group” as used herein refers to a divalent group havingsubstantially the same structure as the monovalent non-aromaticcondensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group” as used herein refers to amonocyclic or polycyclic group having 5 to 60 carbon atoms only asring-forming atoms. The C₅-C₆₀ carbocyclic group may be an aromaticcarbocyclic group or a non-aromatic carbocyclic group. The term “C₅-C₆₀carbocyclic group” as used herein refers to a ring (e.g., a benzenegroup), a monovalent group (e.g., a phenyl group), or a divalent group(e.g., a phenylene group). Also, depending on the number of substituentsconnected to the C₅-C₆₀ carbocyclic group, the C₅-C₆₀ carbocyclic groupmay be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group” as used herein refers to a grouphaving substantially the same structure as the C₅-C₆₀ carbocyclic group,except that at least one heteroatom selected from N, O, Si, P, and S isused as a ring-forming atom, in addition to carbon atoms (e.g., 1 to 60carbon atoms).

In the present specification, at least one substituent of thesubstituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₁-C₂₀ alkylene group, thesubstituted C₂-C₂₀ alkenylene group, the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group,the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, thesubstituted C₁-C₆₀ heteroarylene group, the substituted divalentnon-aromatic condensed polycyclic group, the substituted divalentnon-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀ alkenyl group, the substitutedC₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, thesubstituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedC₁-C₆₀ heteroaryloxy group, the substituted C₁-C₆₀ heteroarylthio group,the substituted monovalent non-aromatic condensed polycyclic group, andthe substituted monovalent non-aromatic condensed heteropolycyclic groupmay be selected from:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthiogroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthiogroup, a monovalent non-aromatic condensed polycyclic group, and amonovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthiogroup, a monovalent non-aromatic condensed polycyclic group, and amonovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, aC₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl groupsubstituted with at least one selected from deuterium, —F, and a cyanogroup, a C₆-C₆₀ aryl group substituted with at least one selected fromdeuterium, —F, and a cyano group, a biphenyl group, and a terphenylgroup.

The term “Ph” as used herein refers to a phenyl group. The term “Me” asused herein refers to a methyl group. The term “Et” as used hereinrefers to an ethyl group. The term “tert-Bu” or “Bu^(t)” as used hereinrefers to a tert-butyl group. The term “OMe” as used herein refers to amethoxy group.

The term “biphenyl group” as used herein refers to a phenyl groupsubstituted with a phenyl group. The “biphenyl group” may be asubstituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as used herein refers to a phenyl groupsubstituted with a biphenyl group. The “terphenyl group” may be asubstituted phenyl group having a C₆-C₆₀ aryl group substituted with aC₆-C₆₀ aryl group as a substituent.

The symbols * and *′ as used herein, unless defined otherwise, refer toa binding site to an adjacent atom in a corresponding formula.

Hereinafter, a light-emitting device according to one or moreembodiments will be described in more detail with reference to Examples.

Examples. Example 1

A 15 Ohms per square centimeter (Ω/cm²) (1,200 Å) ITO/Ag/ITO glasssubstrate (available from Corning Co., Ltd) was cut to a size of 50millimeters (mm)×50 mm×0.7 mm, sonicated in isopropyl alcohol and purewater for 5 minutes in each solvent, cleaned with ultraviolet rays for30 minutes, and then ozone, and was mounted on a vacuum depositionapparatus.

HT3 was deposited on the ITO/Ag/ITO anode of the glass substrate to athickness of 1.7 nm, HT3 and CuI were co-deposited thereon at a volumeratio of 97:3 to form a hole injection layer to a thickness of 8 nm, HT3was deposited on the hole injection layer to form a first hole transportlayer to a thickness of 24 nm, TCTA was deposited on the first holetransport layer to form a second hole transport layer to a thickness of5 nm, H18 and FD23 were co-deposited at a volume ratio of 98:2 on thesecond hole transport layer to form an emission layer to a thickness of17 nm, T2T was deposited on the emission layer to form a first electrontransport layer to a thickness of 5 nm, and TPM-TAZ and LiQ wereco-deposited at a volume ratio of 1:1 on the first electron transportlayer to form a second electron transport layer to a thickness of 25 nm,thereby forming a first emission unit.

Compound N1 and Li were co-deposited on the first emission unit at avolume ratio of 99:1 to form an n-type charge generating layer to athickness of 5 nm, and HT3 and Bi₂Te₃ were co-deposited on the n-typecharge generating layer at a volume ratio of 90:10 to form a p-typecharge generating layer to a thickness of 5 nm. HT3 and CuI wereco-deposited on the p-type charge generating layer to a volume ratio of90:10 to form a p-type hole injection layer to a thickness of 10 nm,thereby forming a first charge generating unit.

HT3 was deposited on the first charge generating unit to form a firsthole transport layer to a thickness of 54 nm, TCTA was deposited on thefirst hole transport layer to form a second hole transport layer to athickness of 5 nm, H18 and FD23 were co-deposited at a volume ratio of98:2 on the second hole transport layer to form an emission layer to athickness of 17 nm, T2T was deposited on the emission layer to form afirst electron transport layer to a thickness of 5 nm, and TPM-TAZ andLiQ were co-deposited at a volume ratio of 1:1 on the first electrontransport layer to form a second electron transport layer to a thicknessof 25 nm, thereby forming a second emission unit.

Compound N1 and Li were co-deposited on the second emission unit at avolume ratio of 99:1 to form an n-type charge generating layer to athickness of 5 nm, and HT3 and Bi₂Te₃ were co-deposited on the n-typecharge generating layer at a volume ratio of 90:10 to form a p-typecharge generating layer to a thickness of 5 nm. HT3 and CuI wereco-deposited on the p-type charge generating layer to a volume ratio of90:10 to form a p-type hole injection layer to a thickness of 10 nm,thereby forming a second charge generating unit.

HT3 was deposited on the second charge generating unit to form a firsthole transport layer to a thickness of 44.5 nm, TCTA was deposited onthe first hole transport layer to form a second hole transport layer toa thickness of 5 nm, H18 and FD23 were co-deposited at a volume ratio of98:2 on the second hole transport layer to form an emission layer to athickness of 17 nm, T2T was deposited on the emission layer to form afirst electron transport layer to a thickness of 5 nm, TPM-TAZ and LiQwere co-deposited at a volume ratio of 1:1 on the first electrontransport layer to form a second electron transport layer to a thicknessof 35 nm, KI and Yb were co-deposited on the second electron transportlayer at a volume ratio of 95:5 to form an electron injection layer to athickness of 1.1 nm, thereby forming a third emission unit.

Ag and Mg were co-deposited on the third emission unit to a volume ratioof 9:1 to form a cathode to a thickness of 12 nm, thereby completing themanufacture of a tandem light-emitting device.

Examples 2 to 5 and Comparative Examples 1 to 7

Light-emitting device were manufactured in substantially the same manneras in Example 1, except that materials illustrated in Table 1 were used.

Evaluation Example may include various features described herein.

The driving voltage, driving voltage change, efficiency, lifespan, andCIE color-coordinate of the light-emitting devices manufactured inExamples 1 to 5 and Comparative Examples 1 to 7 were measured usingKeithley source-measure unit (SMU) 236 and a luminance meter PR650. Theresults thereof are illustrated in Table 1. The lifespan (T97) refers toa period of time required for the initial luminance (100%) of 400 nit ofthe light-emitting device to reduce by 97%. The driving voltage changerefers to the difference between the initial driving voltage and thedriving voltage measured 500 hours after the driving of thelight-emitting device.

TABLE 1 n-TYPE DRIVING DRIVING LIFE- COLOR- HOLE ELECTRON VOL- VOLTAGEEFFI- SPAN COOR- INJECTION CHARGE-GENERATING UNIT INJECTION TAGE @T97CIENCY @T97 DINATE LAYER pHIL pCGL nCGL LAYER (V) (V) (cd/A) (HOURS) (By) EXAMPLE 1 HT3 + Cul HT3 + Cul HT3 + Bi₂Te₃ N1 + Li KI + Yb 10   0.528.7 870 0.13  EXAMPLE 2 HT3 + Cul HT3 + Cul HT3 + Bi₂ N1 + Li KI + Yb10.2 1 27.5 770 0.123 EXAMPLE 3 HT3 + Cul HT3 + Cul HT3 · Bi₂ N1 + LiKI + Yb 10.1 0.8 28.2 830 0.133 EXAMPLE 4 HT3 + Cul HT3 + Cul HT3 +Bi₂Te₃ N1 + Yb KI + Yb 10.2 0.7 28.4 810 0.128 EXAMPLE 5 HT3 + Cul HT3 +ZnTe HT3 + Bi₂Te₃ N1 + Li KI + Yb 10.5 1.2 27.7 750 0.122 COMPAR- —HT3 + Cul HT3 + Bi₂Te₃ N1 + Li KI + Yb 12.2 4.2 25   250 0.126 ATIVEEXAMPLE 1 COMPAR- m-TDATA + HT3 + Cul HT3 + Bi₂Te₃ N1 + Li — 12.6 5.117    10 0.112 ATIVE BiF3 EXAMPLE 2 (40%) COMPAR- HT3 + Cul HT3 + CulHT3 + Bi₂Te₃ N1 + Li — 10.8 1.2 26   640 0.134 ATIVE EXAMPLE 3 COMPAR-HT3 + Cul HT3 + Cul HT3 + Bi₂Te₃ Bphenyl + KI + Yb 10.3 1.5 25.6 4500.122 ATIVE Li (2%) EXAMPLE 4 COMPAR- HT3 + Cul HT3 + Cul HT3 + Bi₂Te₃COMPOUND KI + Yb DEVICE NOT OPERATIVE ATIVE A + Bil₃ EXAMPLE 5 (1.1)COMPAR- HT3 + Cul — HT3 + Bi₂Te₃ N1 + Li KI + Yb 15.3 5.6 11    5 0.127ATIVE EXAMPLE 6 COMPAR- HT3 + Cul m-TDATA + HT3 + Bi₂Te₃ N1 + Li KI + Yb14.8 6.1 12.1  7 0.133 ATIVE BiF3 EXAMPLE 7 (40%)

As illustrated in Table 1, the light-emitting devices of Examples 1 to 5were found to have low driving voltage increases, improved efficiencyand lifespan, and in particular, improved lifespan, as compared with thelight-emitting devices of Comparative Examples 1 to 7.

As apparent from the foregoing description, in the light-emittingdevice, a charge generating unit may have a structure including ann-type charge generating layer, and a p-type charge generating layer,and a p-type hole injection layer, balance of holes and electrons areimproved, thus realizing a low driving voltage and excellent efficiencyand lifespan characteristics.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While one or more embodiments have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope asdefined by the following claims.

What is claimed is:
 1. A light-emitting device comprising: a firstelectrode; a second electrode facing the first electrode; and an organiclayer between the first electrode and the second electrode, wherein theorganic layer includes m emission units and (m−1) charge generatingunits, each of the charge generating units being between the emissionunits that are adjacent to each other, m is a natural number of 2 orgreater, at least one of the (m−1) charge generating units includes ann-type charge generating layer, a p-type charge generating layer, and ap-type hole injection layer, wherein the n-type charge generating layerincludes an n-type organic compound and a metal material, and whereinthe p-type charge generating layer and the p-type hole injection layereach independently include an inorganic semiconductor material.
 2. Thelight-emitting device of claim 1, wherein the n-type organic compoundincluded in the n-type charge generating layer includes: aphenanthrene-based compound or a phosphine oxide-based compound.
 3. Thelight-emitting device of claim 1, wherein the metal material included inin the n-type charge generating layer has at least one metal selectedfrom an alkali metal, an alloy of an alkali metal, an alkaline earthmetal, an alloy of an alkaline earth metal, a lanthanide metal, and analloy of a lanthanide metal.
 4. The light-emitting device of claim 1,wherein the metal material included in the n-type charge generatinglayer has at least one component selected from lithium (Li), sodium(Na), a Bi—Li alloy, a Bi—Na alloy, ytterbium (Yb), samarium (Sm),europium (Eu), terbium (Tb), holmium (Ho), and dysprosium (Dy).
 5. Thelight-emitting device of claim 1, wherein a binding energy between then-type organic compound and the metal material included in the n-typecharge generating layer is 1.25 electron volts (eV) or higher.
 6. Thelight-emitting device of claim 1, wherein a volume ratio of the n-typeorganic compound to the metal material included in the n-type chargegenerating layer is in a range of about 99.9:0.1 to about 80:20.
 7. Thelight-emitting device of claim 1, wherein the inorganic semiconductormaterial included in the p-type charge generating layer and theinorganic semiconductor material included in the p-type hole injectionlayer are each independently a post-transition metal, tellurium, ahalide of a transition metal, a halide of a post-transition metal, atelluride of a transition metal, a telluride of a post-transition metal,a sulfide of a transition metal, a sulfide of a post-transition metal, aselenide of a transition metal, a selenide of a post-transition metal,or any combination thereof.
 8. The light-emitting device of claim 1,wherein the p-type charge generating layer and the p-type hole injectionlayer each independently further include a hole transporting organiccompound.
 9. The light-emitting device of claim 8, wherein the holetransporting organic compound included in the p-type charge generatinglayer and the hole transporting organic compound included in the p-typehole injection layer each independently have at least one selected froma compound represented by Formula 201 and a compound represented byFormula 202:

wherein, in Formulae 201 and 202, L₂₀₁ to L₂₀₄ are each independentlyselected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group,a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,L₂₀₅ is selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group, xa1 to xa4 are eachindependently an integer from 0 to 3, xa5 is an integer from 1 to 10,and R₂₀₁ to R₂₀₄ and Q₂₀₁ are each independently selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.10. The light-emitting device of claim 8, wherein a volume ratio of thehole transporting organic compound to the inorganic semiconductormaterial in the p-type charge generating layer and a volume ratio of thehole transporting organic compound to the inorganic semiconductormaterial in the p-type hole injection layer are each independently in arange of about 99.9:0.1 to about 80:20.
 11. The light-emitting device ofclaim 1, wherein a m^(th) emission unit that is a m^(th) emission unitfrom the first electrode among the m emission units includes a m^(th)hole transport region, a m^(th) emission layer, and a m^(th) electrontransport region, and the m^(th) electron transport region includes aninorganic insulating material.
 12. The light-emitting device of claim11, wherein the m^(th) electron transport region includes an n-typeelectron injection layer, and the n-type electron injection layerincludes the inorganic insulating material.
 13. The light-emittingdevice of claim 12, wherein the n-type electron injection layer is indirect contact with the second electrode.
 14. The light-emitting deviceof claim 11, wherein the inorganic insulating material includes a halideof an alkali metal, a halide of an alkaline earth metal, a halide of alanthanide metal, or any combination thereof.
 15. The light-emittingdevice of claim 12, wherein the n-type electron injection layer consistsof the inorganic insulating material.
 16. The light-emitting device ofclaim 12, wherein the n-type electron injection layer further includes ametal dopant, and the metal dopant includes at least one selected froman alkali metal, an alloy of an alkali metal, an alkaline earth metal,an alloy of an alkaline earth metal, a lanthanide metal, and an alloy ofa lanthanide metal.
 17. The light-emitting device of claim 16, whereinthe metal dopant is selected from ytterbium (Yb), samarium (Sm), lithium(Li), and magnesium (Mg).
 18. The light-emitting device of claim 16,wherein a volume ratio of the inorganic insulating material to the metaldopant is in a range of about 100:0 to about 70:30.
 19. An apparatuscomprising: a thin-film transistor including a source electrode, a drainelectrode, and an active layer; and a light-emitting device according toclaim 1, wherein the first electrode of the light-emitting device iselectrically connected to one of the source electrode and the drainelectrode of the thin-film transistor.
 20. The apparatus of claim 19,further comprising: a color filter, wherein the color filter is on apathway of light emitted from the light-emitting device.